1. Field of the Invention
The preset invention relates to a rotation shaft, more particularly to a structure of rotation shaft capable of preventing connected objects, e.g. a display monitor, from vibrating.
2. Description of Related Art
For commercial electronic good, e.g. a portable computer, a mobile phone, an electronic dictionary and a portable audio/video playing device, etc, its main portion is mostly disposed below its cover and a rotation shaft is provided to connected the main portion and the cover, so the cover can be opened or closed, relative to the main portion, therefore the rotation shaft plays an crucial role on determining the quality of the goods mentioned above.
A conventional rotation shaft is mainly composed by a retaining member and a mobile member pivotally connected to the retaining member, and a desired positioning effect is obtained by the friction generated by the two above mentioned members relatively rotating. As shown in FIG. 1, which is a 3D exploded view of a conventional structure of rotation shaft, a lateral connecting section 42 of a main body 41 of the mobile member 40, e.g. a supporting rack, is connected to a long-stripe shaped rack member for connecting to one side of a display screen, and a free end of an extending section 43 disposed below the main body 41 is bended or winded so at least one clamping ring 44 is formed, the clamp rings 44 are mounted and connected by a retaining member 50, e.g. a rotation rod 51 of a pivotal shaft, so a pivotal connection status is formed. When the supporting rack rotates, a friction is generated on a fiction plane between the rotation rod 51 and the clamping rings 44 so a structure of rotation shaft is formed.
Because the clamping rings 44 are formed by bending or winding metals, axial shaft holes 45 thereof are not in a real round shape. When the shaft holes 45 of the clamping ring 44 rotate with the shaft rod 51 of the pivotal shaft as a rotation core, the vibration generated at gaps between the shaft holes 45 and the shaft rod 51 are overly long so wearing of the two members mentioned above are increased and the service life are therefore shortened. The extending section 43 is extended from the main body 41 of the supporting rack and formed as one piece with the main body 41, the thickness of the extending section 43 is not enough so the rigidity thereof is not strong and has flexibility, this also results in the vibration of the display screen is overly long.
Taiwan Patent No. 545618, corresponding to U.S. Pat. No. 6,657,856, entitled “Fixing structure for preventing the screen of notebook computer from bouncing and vibrating” has disclosed a structure formed on a pivotal device of a notebook computer screen and used to prevent vibration when opening the screen, wherein one side of a prime sheet member assembled between the pivotal device and the screen housing is provided with an installation block for supporting sheet, the installation block for supporting sheet of the prime sheet member is provided with a supporting sheet that is vertical to the prime sheet member and capable of contacting with the screen housing, the screen housing is supported by the supporting sheet so the vibration during opening is reduced. The installation block for supporting sheet and the supporting sheet provided by the patent mentioned above are combined in a mounting fashion, so the combination is often unstable or loose which is needed to be improved.